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Editors' Choice

Alien defeated by native fungi

The spotted lanternfly, Lycorma delicatula, is an invasive pest insect of woody plants in many countries.

PHOTO: STEVE AUSMUS/USDA/ARS

Within the past 4 years, Lycorma delicatula, an Asian planthopper, has become an invasive pest in the eastern United States. It can feed on many woody and ornamental plant species and thus poses a direct threat to agriculture. This insect can reach high densities, perhaps because it has escaped its natural parasites and pathogens. However, in late 2018, Clifton et al. spotted a mass die-off of the insect. They found that before they were able to lay eggs, the planthoppers were attacked by two species of local fungi, Beauveria bassiana and Batkoa major. It remains to be seen whether the fungi will be able to keep the insect populations below damage thresholds, whether they also affect native insects as the environment becomes laden with fungal spores, or whether they trigger boom-and-bust cycles of the pest.

Proc. Nat. Acad. Sci. U.S.A. 10.1073/pnas.1903579116 (2019).

Education

Graduate students under pressure

Melissa McCartney

Graduate students in STEM are facing an escalating mental health crisis. How can the STEM community best understand and address the factors underlying the well-being of graduate students? Sverdlik and Hall recruited 3004 doctoral students, who completed an online survey, to determine whether doctoral program phase (coursework, comprehensive examination, or dissertation) had an effect on well-being levels (stress, depression, program satisfaction, and illness symptoms) and motivation (self-determined motivation and self-efficacy). Results showed that well-being and motivation are high during the coursework phase and very low during the comprehensive examination phase. Although this work is preliminary, it suggests that departmental efforts to clarify expectations and provide support during this transition may help to mitigate this expected drop in well-being levels.

J. Adult Contin. Educ. 10.1177/1477971419842887 (2019).

Conservation

A keener eye

Cane toad toxin is endangering native goannas, such as this Varanus panoptes, in Australia.

PHOTO: NICK ASHCROFT/ALAMY STOCK PHOTO

Conservation actions are sometimes most pressing in areas where local people are excluded from research activities. This not only has clear ethical drawbacks but may also reduce research effectiveness. Ward-Fear et al. included Australian Aboriginal rangers in their study of training effects on cane toad avoidance in yellow spotted monitor lizards. They found that the rangers not only identified lizards at longer distances but also more readily discovered lizards that displayed shyer personalities and occupied more vegetated and shaded areas, whereas the scientists identified lizards that were bolder and more obvious. Ranger-identified lizards were also more successful at being trained to avoid toxic cane toads, likely because they behaved in more risk-averse ways. This study emphasizes the importance of cultural diversity in research teams to the quality of research outcomes.

Cons. Lett. 10.1111/conl.12643 (2019).

Cell Biology

Membrane proteins up close

Stella M. Hurtley

Techniques to visualize intracellular membrane proteins at the ultrastructural level are often constrained by difficulties in maintaining membrane morphology for electron microscopic analysis. Sengupta et al. developed an electron tomography approach that overcomes some of these difficulties. CryoAPEX combines chemical fixation, high-pressure freezing, and peroxidase tagging to preserve intracellular membrane morphology. The authors successfully elucidated the membrane distribution and ultrastructure of a protein involved in posttranslational modification of proteins within the endoplasmic reticulum of cultured cells. This approach should be applicable to proteins in other membranous compartments and allow detailed analysis of specific protein distribution within the secretory pathway, lysosomal-endosomal system, and other membrane-bound organelles.

J. Cell Sci.132, jcs222315 (2019).

Gut Signaling

Sniffing out ligands for receptors

Michael A. Funk

Our sense of smell comes from a myriad of olfactory receptors expressed in neurons in the olfactory bulb of the nose, each of which responds to different chemical activators. Some of these receptors are also expressed in tissues associated with more noxious odors. Yasi et al. created yeast sensor strains for seven receptors expressed in the human colon. Testing a panel of 57 chemicals, the authors found that several receptors could be activated by small-molecule ligands. These sensor strains should be useful for rapid testing of larger ligand screens, which will help establish the activation profile and physiological functions of these receptors in the colon.

Biochemistry58, 2160 (2019).

Cancer

Generational cancer

Beverly A. Purnell

Our surroundings can not only affect us but can also affect future generations by causing epigenetic changes to DNA. Some cancers show marked intergenerational effects that are difficult to explain. Lesch et al. show that in mice, the heritability of cancer can be attributed to epigenetic changes. The authors engineered a mutation into mouse sperm at a gene called Kdm6a (also called Utx), which controls the placement of epigenetic marks. Despite inheriting a normal copy of the Kdm6a gene from the mother, offspring developed more tumors than mice produced from normal sperm. Tumor incidence was even greater in a second generation. Drugs targeting epigenetic regulators are used to treat cancer, but these may have deleterious intergenerational effects, which need to be considered in therapeutic regimens.

eLife8, e39380 (2019).

Greenhouse Gases

Not so fast

H. Jesse Smith

Methane emissions from oil and natural gas production in the United States may not be rising as quickly as had been feared. Methane is a potent greenhouse gas that is emitted during the natural gas production cycle, so the nearly 50% increase in natural gas production from 2006 to 2015 raised the concern that emissions have risen too. Lan et al. found that this is not the case and that, in fact, total methane emissions have remained essentially constant over that period. They suggest that the overestimates of some recent studies are a function of a decreasing ratio of methane to ethane emissions.